The present invention relates to an information distribution system for distributing proprietary information, such as an image, for sale and a billing system used for the information distribution system.
This application is based on Japanese Patent Application No. 8-259433, filed Sep. 30, 1996, Japanese Patent Application No. 8-345971, filed Dec. 25, 1996, Japanese Patent Application No. 9-45541, filed Feb. 28, 1997 and Japanese Patent Application No. 9-60406, filed Mar. 14, 1997, the content of which is incorporated herein by reference.
In recent years, several information distribution systems are proposed which provides information as goods, which are electronic information, such as so-called multimedia information, for a user (a buyer of the goods) through a communication medium such as a computer network or a digital satellite broadcast or an information recording medium, such as a DVD (Digital Versatile Disk). For example, NTT proposed an information distribution system called FleaMarketm which uses the Internet as the communication media.
Multimedia information means information, such as a movie formed by combining image, audio and character (text) information items. Proprietary information include, in addition to the multimedia information, news information corresponding to an article of a newspaper or a magazine consisting of character information and still image information, information on a catalogue of goods and music composed of only audio information.
To realize an information distributing system, a so-called billing system for billing a user accurate charges (fees) is required when the information is provided and utilized. The billing system realizes a mechanism for paying the fees or charges to a provider of the information, a person having the copyright or a distributor of the information.
As compared with the usual provisions of products or goods, the provision of information has a variety of forms. Specifically, the information are in the form of an electronic file stored in a magnetic disk apparatus or an optical disk apparatus connected to a computer so as to be supplied to a computer of the user through an information recording medium or a communication medium. The information may be transformed into another shape, such as an image or voice which is a continuous analog information so as to be reproduced on a television receiver or a screen of a personal computer.
The charge of the proprietary information is determined in accordance with the information form and the provision form. If information is in the form of a file, the charge may be determined in unit of file or others (for example, in unit of byte) in accordance with the size of the file. Note that "the information in the form of a file" is information which exists on the provider side in the form of a file and which is downloaded or information which is continuously supplied so as to be stored in a file system of the user apparatus. If information is image information, such as a movie, the charge may be determined in unit of reproduction time (a period of time of usage) or unit of title (of the movie). In addition to uniform charge, a reduction rate may be introduced into the billing system, according to the usage time or the usage amount of information.
Some information are composed of a plurality of information contents. Specifically, there are information simultaneously providing an image and voice, the copyrights of which are owned by different persons, or information (corresponding to a virtual compact disk (CD)) formed by collecting music titles, the copyrights of which are owned by different persons. For a billing system adaptable to the above-mentioned complex information, a billing to a user results in processes for paying the charge to all persons having the copying corresponding to the contents. In this case, a provider of the information may pay the charge to each of the persons each having the copyright.
Moreover, the billing system must specify a charge settlement method in addition to the billing method (which means the methods of metering the charge in predetermined units) for proprietary information. Specifically, as a settlement method, a credit card, or a prepaid card, etc., are available now, and so-called electronics money will be available in future. The above-mentioned various settlement methods are adapted to the information according to the property of the contents and the method of providing information. It is preferable that a plurality of settlement methods be set to one information item to permit a user and the provider of the information to arbitrarily select a settlement method.
Since the information are provided in special and various forms as compared with usual goods and products, the persons having copyrights and the provider of the information must perform a complicated process of setting an arbitrary billing method and settlement method to perform a predetermined billing process. Moreover, a large quantity of process must be performed. As described above, the billing method includes a large number of forms, such as billing corresponding to the time in which the information (information provision) is given, billing corresponding to the quantity (bytes) of provided information and billing in a lump for a movie. At present, in an information distribution system, only one billing method determined by the provider of the information is employed. Specifically, a billing program is included in an application program installed on a user terminal or a server of the information provider. Therefore, change of the billing method requires rewriting of the application program and thus there arises a problem in that the billing method cannot easily be changed. Another problem arises in that a new billing method cannot easily be added and it is not permitted to select a billing method because the program must considerably be changed.
Since multimedia information providing services becomes popular in recent years, a case is increased in which one user makes a contract with a plurality of information providers to receive a plurality of information. In this case, the conventional billing function is implemented as a part of the application program. Therefore, when a new application program is produced, the billing function must be implemented in it. There arise problem in that an excessively long time is required to develop a billing program for each application program and the size of the program is enlarged and the structure of the program is complicated excessively.
For providing information, such as a movie or a music, having a real-time characteristic, a billing system of the foregoing type is usually performed such that the billing process is performed in a real-time manner in parallel to the process for providing information. Therefore, if plural information provisions are performed concurrently, the billing processes are performed concurrently too. Thus, there arises a problem in that the load of the billing process on the system becomes too heavy. In either of the time rate billing method or the byte rate billing method, the quantity of the billing process is enlarged if the unit (or rate) of billing is small. Therefore, the concentration of the billing processes caused from the enlargement of the billing process sometimes results in the load of the system being enlarged to exceed the allowable load. Thus, the normal billing process cannot be performed sometimes at worst. The reason why the billing process must be performed in a real-time manner is that the balance of an account of a bank or the permitted limit of a credit card has a possibility that it is changed because of use in response to another requirement. Therefore, a risk that the charge cannot be collected must be avoided and thus the real-time billing process must be performed.
It might be considered feasible to employ a job scheduling method (a method in which a job having a low priority is brought to a standby mode) of the operating system to adjust the operation of the system if the load of the computer system is made heavier. However, if the foregoing billing system employs the method in which a certain process is simply brought to the standby mode, generation of time delay raises the possibility of the fact that the valid billing process cannot be performed.